1. Field of the Invention
The present invention relates to fastener means for joining a frame shell and two panel members and more particularly, to a panel member locking device, which comprises a bracket affixed to a frame shell, a driving rod, a guide tube for guiding the driving rod to move axially up and down relative to the bracket, a constraint member coupled between the driving rod and the bracket for guiding the driving rod to rotate relative to the bracket, a spring member sleeved onto the guide tube and stopped between a head block of the guide tube and a shoulder inside the bracket, and a locking rod connected to the bottom end of the driving rod and movable and rotatable by the driving rod for detachably locking two stacked panel members at the frame shell.
2. Description of the Related Art
When joining panel members, fastening devices respectively formed of a screw nail, a rotary knob and a washer may be used. During application, the screw nail, rotary knob and washer of each fastening device are assembled and then mounted at a first panel member. When fastening the first panel member to a second panel member, rotate the rotary knob of each fastening device to drive the respective screw nail into a respective mounting screw hole at the second panel member. This multiple panel member fastening method can be used in a machine tool or other situations where multiple panel members are to be fastened in a stack. In a machine tool, the location where panel members are fastened together may be at the power drive or speed-adjustment unit inside the housing. The screw nails of the fastening devices may fall from the panel members and missed easily due to user's negligence during a panel member dismounting procedure, affecting further re-installation operation.
Further, with continuous innovation and progress of computer technology, the application of computers and many other electric and electronic products has been greatly enhanced and improved. Hard disk drive, CD-ROM, BD/DVD/DC duplicator, power adapter, and/or any of a variety of other peripheral devices may be installed in a computer or any of a variety of other electric and electronic products to expand the function. These attached devices may be fastened to the frame shell of the product with tie screws. However, mounting and dismounting the tie screws must use a screwdriver. Further, these tiny tie screws may be missed easily during the mounting or dismounting operation. To facilitate quick mounting and dismounting between the frame shell of a product and panel members of attached devices, a panel member locking device is created. As shown in FIGS. 8 and 9, this conventional panel member locking device A comprises a bracket A1 affixed to a frame shell B and providing a transverse sliding slot A23, a driving rod A2 axially movably and rotatably mounted in the bracket A1, a swivel handle A21 coupled to the headed top end of the driving rod A2 outside the bracket A1, a spring member A25 sleeved onto the driving rod A2 and supported between the headed top end of the driving rod A2 and an inside part of the bracket A1, a guide block A24 coupled between the transverse sliding slot A23 of the bracket A1 and the driving rod A2 to limit the rotation angle of the driving rod A2 relative to the bracket A1, and an externally threaded locking rod A22 connected to the bottom end of the driving rod A2. A user can operate the swivel handle A21 to lower the driving rod A2 and the externally threaded locking rod A22 and then to rotate the driving rod A2 and the externally threaded locking rod A22, inserting the externally threaded locking rod A22 through a through hole (not shown) at a first panel member C1 and driving the externally threaded locking rod A22 into a mounting screw hole C3 at a second panel member C2 to lock the first panel member C1 and the second panel member C2 at the frame shell B. In actual application, this design of panel member locking device A still has drawbacks as follows:    1. Subject to the constraint of the matching between the guide block A24 and the transverse sliding slot A23, the driving rod A2 can simply be rotated through a half round (180°), thus, the depth of engagement of the externally threaded locking rod A22 in the mounting screw hole C3 at the second panel member C2 is limited, and therefore the externally threaded locking rod A22 may be forced out of the mounting screw hole C3 at the second panel member C2 accidentally by an external force.    2. The driving rod A2 is rotatable relative to the bracket A1 through a half round (180°) subject to the constraint of the matching between the guide block A24 and the transverse sliding slot A23 without any positioning means, and the spring power of the spring member A25 may force the driving rod A2 to move the locking rod A22 away from the through hole of the first panel member C1 and the mounting screw hole C3 of the second panel member C2.    3. When the user operates the swivel handle A21 to rotate the driving rod A2 relative to the bracket A1, the user may rotate the locking rod A22 in the mounting screw hole C3 of the second panel member C2 in the wrong direction, resulting in locking instability.    4. The swivel handle A21 is formed of a metal wire rod not convenient to grasp, and therefore it is inconvenient to rotate the driving rod. A2.    5. Due to thin wall thickness of the mounting screw hole C3 of the second panel member C2, the contact area between the locking rod A22 and the second panel member C2 is limited, providing a low locking strength.
Therefore, it is desirable to provide a panel member locking device, which facilitates installation and locking operation and assures a high level of locking stability and tightness.